Mechanical Properties and Flexural Strength of Reinforced Concrete Beams Containing Waste Material as Partial Replacement for Coarse Aggregates

The volume of waste materials and by products are increasing and endangering the environment safety. Some of these waste materials can be used in the production of building materials, such as concrete. In order to study the possibility of using some waste materials as aggregate replacement for the purpose of producing structural RC members this investigation was carried out. This research describes the results of test of reinforced concrete beams containing different types of waste materials, namely crumbed rubber, granular plastic, and crushed bricks. Ten RC beams containing different percentages (0%, 5%, 10%, and 15%) of waste materials as coarse aggregate replacement have been investigated. The beams were 150 × 200 mm in size and 2000 mm in length and tested under four points loading. Mechanical properties of the concrete used for the beams were also studied. Test results indicated a reduction in compressive strength, splitting tensile strength, and elastic modulus due to the inclusion of the waste materials used. The maximum loss in concrete compressive strength was recorded to be 54.95%, 50.31%, and 20.41% for concrete mix with 15% crumbed rubber, plastic waste aggregate, and 5% crushed brick, respectively. Test results of the beams showed that ultimate load capacity was reduced by 30.21% and 9.94% when 15% of crumbed rubber and granular plastic were used, respectively. The failure mode of all the tested beams was similar and followed same pattern, steel yielding followed by concrete compression failure. Finally, based on the flexural capacity of the beams tested it is recommend that gravel replacement of up to 15% of crumbed rubber, granular plastic, and crushed brick can be safely used to produce normal type of RC beams for minor structural application.